Each journal is assigned to one of 22 research fields. In ESI, a journal can be assigned to only one field. Journals such as Science and Nature are categorized as multidisciplinary since they publish research in many different fields. As a result, papers published in these multidisciplinary journals are assigned to a field based on the representation of the cited journals. For example, if the majority of citations to a paper published in Science come from neuroscience journals and the majority of cited references in the paper are to neuroscience journals, the paper is then categorized as neuroscience.

Journal List

The master journal list comprises all journals covered for Essential Science IndicatorsTM as of March 5of May 7, 2015 , to cover an 11to cover a 10-year plus 02-month period, January 1, 2004 2005-December 31February 28, 20142015. This is the sixth Data is updated bimonthly (six times a year). This is the first bimonthly period of 2014. Journals are listed alphabetically within each of the 22 fields covered by the database. Where available, journal ISSNs have been supplied.2015.

This master journal list will be updated regularly. The current extraction date is February 25April 1, 2015.